True, that is why I used those colors
The thing with seperate game farming is you need 3 other people who you completely trust because if someone is slacking it won't be efficient. And yes you can interrupt goblins escape but only up to a certain time. Its portal becomes uninterruptable after 40-50seconds you engage him which is a enough time for others to join you. That strategy might be better but everyone must be doing their part, most of the time %50 of my party used to be random pugs that's why I sticked to same game farming.
About the maps, for example the Arreat core in act3, had a very low chance of spawning goblins. I found atleast x5 more goblins in leoric's passage compared to Arreat Core and there are a few more examples like that, atleast regarding my experience. It might be different for everyone.
And thanks for the point about people who thinks they must be in the area when rgb is killed, I will add that the guide.